Use Latest version Of winrar or 7-Zip
Extract .rar file ..
Extract To Short Paths Like C:Games Or D:Games
Go To The Extracted Folder And Double Click On The MOHAA.reg File(Click YES Then OK)(MUST BE DONE) Then Double Click On The MakeDesktopIcon & File.
Start The game from the desktop.
Simple as that :

FULL GAME
Install &gt;NOTHING&lt;
Play &gt; EVERYTHING&lt;

When You no longer want the game on your Computer, delete the extracted folder and the desktop Shortcut..